Method of cleansing filter-beds.



z. VON WBSSELY.

METHOD 0F GLEANSING FILTER BEDS.

APPLIUATION FILED JULY 14. 190s.

944,527, rvPatented Dec.28,1909; Fia-1- 55 /f/ "H f4 /ff/ 9/ 4///, 07

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ZDENKO VON WESSELY, OF PRAGUE, AAUS'.llRlLA-I-fUNGARY.

METHOD OF CLEANSING FILTER-BEDS.

To all whom 'it 'may concern.'

Be it known that I, ZDENKO VON WESSELY, subject of the Emperor of Austria-Hungary, residing at Prague, in the Empire of Austria-Hungary, have invented certain new and useful Improvements in Methods of Cleansing Filter-Beds, for which application has been made in Germany, dated February 25, 1907.

This invention relates to an improved process of cleaning sand in filter beds.

Sand filters have hitherto been cleaned by washing, water and air being alternately or simultaneously conveyed through the sand bed in a stream inthe opposite direction to the flow when filtering.

The process of cleaning the sand in sand filters, which forms the object of the present invention is based on the use of water or air under pressure, which is conducted into the interior of the sand bed, but the present process differs from those already known in that the cleaning` of the sand can be elfected at various levels, particularly in the uppermost layers of the sand, in which the socalled filter film is formed by the gradual deposition of the substances retained.

The process consists in the sand at the desired levels of the bed being turned over and thrown to and fro by water or air currents, in order to wash away and rub off the particles of dirt adhering to the sand, not only by the movement of the water or mixture of air and water flowing around the sand grains, but also by the friction of the surfaces of the separate sand grains one on another produced by this movement.

The following example is given as indicating the manner in which the process is carried out.

An apparatus illustrating the invention is shown in the accompanying drawing, in which- Figure l is a plan view; and Fig. 2 a cross section.

Two sets of pipes are arranged at a suitable depth in the filter bed. These pipes a and are parallel and all at the same level and the members of the two sets are disposed alternately. Discharge .apertures are arranged along the sides of the pipes so that water or air may be discharged later- Specification of Letters Patent.

Application filed .Tuly 14, 1908.

Patented Dec. 28, Y1909.

Serial No. 443,538.

ally therefrom. Controlling valves are provided so that the two sets may be supplied with the cleaning lluid alternately.

When the surface of the sand of the filter is to be cleaned and any filter film deposited thereon removed, the water level is first lowered in the filter, so that the flushing pipes, being approximately in the plane of 'the surface of the filter sand, are at a very small distance below the water level. The cleansing fluid (water or air) is then admitted under pressure to one of the sets of pipes and being discharged from the side apertures therein throws away the sand situated adjacent thereto laterally while a hollowing out takes place by hydraulic action beneath and beside the pipes. The sand thus thrown aside lodges on the adjacent pipes which are not in operation. If now, after shutting off the supply from the one set of pipes, the cleansing fluid is admitted to the other set, the sand deposited over these pipes will be thrown back again toward the other pipes. Thus by the alternate discharge of water or air under pressure from the two series of pipes, the sand is thrown to and fro from one flushing pipe to thev other until it has reached the desired degree of purity.

I declare that what I claim is l. A process of cleaning the sand in filter beds, which consists in applying alternate currents of cleansing fluid by means of alternately operated perforated pipes arranged in proximity to each other exactly at the level of the surface of the filter sand, so that the latter, by the action of the fluid under pressure, is alternately scooped out in proximity to the pipes which are in operation and accumulated over the pipes which are ysand thereby, and causing said currents to flow alternately in opposite directions so as to give a to and fro movement to the sand substantially as described.

3. A process of cleaning sand in filter beds which consists in applying cleansing fluid to the sand in the forni of parallel rows of jets my name this 80th day of June 1968, in the and at intervals' reversing the directicm of presence of two subscribing Witnesses. the -ets o eratinor u on each art o ther sandl, so tht the smdpduring thvvashing is ZDENKO VON WESSELY' 5 constantly thrown to and fro by the jets, l Witnesses:

substantially as described. ROBERT WV. HEINGARTNER,

In Witness whereof, I have hereunto signed AUGUST FUGGER. 

